The aim of this research is to construct general-purpose models for simulating and displaying the simultaneous electrical activity of large number of inter-connected neurons, and to use these models to help elucidate the dynamical properties of specific neuronal subsystems. Our main specific goals for the two-year period of this application are: 1. to develop a general-purpose analog model to simulate and display the simultaneous activity of large numbers of interconnected neurons in arbitrary configurations, 2. to develop digital computer techniques with particular inclusion of recently developed continuous-system simulation languages and interactive-computer-graphics systems for the same end, and 3. to use these systems to help spell out dynamical properties of reticularlike networks as they occur in the spinal cord, brain stem, and the limbic system of vertebrates, and of various other neuronal networks. The modeling is carefully conceptualized to work closely with experimentation to help produce progress in the problem area generally.